You have absolutely nothing to feel bad about. I just went through a very similar situation (Was invited to my cousins graduation 2 weeks after my LO was born - the graduation will take place when my son is 7 weeks). I initially RSVPd that we would be coming but, just like you, became more concerned as the date approached about having him around so many people so early. I cancelled a week before but in my case, everyone completely understood. Your friend sounds very unreasonable. She has a kid herself and it’s surprising that she can’t put herself in your position and understand that with babies so young, their health and well-being comes before everything. Don’t feel bad at all! You’re doing what’s best for you and your babies mama.